Objective To investigate the effects and significance of nerve growth factor (NGF) and its high affinity receptor of tyrosine kinase A (TrkA) expressions on proliferative connective tissue of bile duct in rats after bile duct ligation (BDL). Methods Forty-six female Sprague-Dawley rats were randomly divided into two groups: control group ( n =6) and BDL group ( n =40). The model of obstructive jaundice in rat was made by bile duct ligation, then duodenohepatic ligament was taken and treated with anti-NGF and anti-TrkA receptor antibody. Expressions of NGF and TrkA receptor in connective tissue of bile duct were investigated by immunohistochemistry, blood specimens were collected from left ventricle to detect serum total bilirubin (TB) and alanine aminotransferase (ALT). Results After BDL, TB level obviously elevated in the third day, and continued until the fourteenth day, then descended. By day 21 and 28, it returned to normal level. Compared with normal bile duct, due to bile stasis, an increased thickness of the bile duct wall was observed by microscope which correlated with the proliferation and differentiation of connective tissue cell. NGF and TrkA were expressed by the cell membrane and the cytoplasm of connective tissue cell and inflammatory infiltration cell after BDL. The trend between their expressions and bilirubin levels was similar. Conclusion NGF and its receptor TrkA regulate the proliferate and differentiation of connective cell in bile duct. They may play a key role in the formation of bile duct scar, which seems to be hardly reversed by relief of bile stasis in a short time.
Objective To investigate the role of IFN-γ in suppressing bleomycin-induced pulmonary fibrosis in rats.Methods Seventy-five SD rats were randomly divided into five groups (15 rats in each group)，ie.a normal group，a bleomycin-induced pulmonary fibrosis model group，a dexamethasone-treated group，a high-dose IFN-γ-treated group (150 000 U/kg) and a low-dose IFN-γ-treated group (50 000 U/kg).Five rats in each group were randomly killed in 7th day，14th day and 28th day after relative treatment respectively，and lung tissue samples were harvested for histopathology study.HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis respectively.Histoimmunochemical method were adapted to determine protein levels of TGF-β1，CTGF，type Ⅰcollagen and type Ⅲ collagen in pulmonary tissues.Results Histopathological study showed that treatment with either dexamethasone or IFN-γ (both high dose and low dose) remarkably meliorated the extent of alveolus inflammation and suppressed pulmonary fibrosis (compared with model group，all Plt;0.05).Histoimmunochemical study suggested that both dexamethasone and IFN-γ could inhibit the expression of TGF-β1，CTGF，type Ⅰand type Ⅲ collagen (compared with model group，all Plt;0.05)，and the suppression of TGF-β1，type Ⅰand type Ⅲ collagen expression was more obvious in high-dose IFN-γ-treated group than those in low-dose group (Plt;0.05).Conclusions INF-γ possesses apparent anti-fibrosis effect that is similar to dexamethasone but with less side effect.Such effect may resulted from reduced production of type Ⅰand type Ⅲ collagen through expression inhibition of cytokines such as TGF-β1 and CTGF.
Objective To investigate the effects of matrine on cell proliferation and expression of connective tissue growth factor( CTGF) and hypoxia inducible factor-1α( HIF-1α) of human lung fibroblast ( WRC-5) in normoxia ( 21% O2, 74% N2 , 5% CO2 ) and hypoxia ( 1% O2, 94% N2 , 5% CO2 )conditions. Methods MRC-5 cells were cultured and divided into differrent groups interfered with different dose of Matrine ( final concentration of 0 ～3. 2 mmol / L) in normoxia or hypoxia for 24 h. Cells were dividedinto 8 groups according to culture conditions, ie. normoxiagroup( N0 group) , normoxia + matrine 0. 2 mmol / L group( N0. 2 group) , normoxia + matrine 0. 4 mmol / L group( N0. 4 group) , normoxia + matrine 0. 8 mmol / L group( N0. 8 group) , hypoxia group( H0 group) , hypoxia + matrine 0. 2 mmol /L group( H0. 2 group) , hypoxia +matrine 0. 4 mmol /L group( H0. 4 group) , and hypoxia + matrine 0. 8 mmol / L group( H0. 8 group) . The MTT assay was used to measure the cell proliferation activity. Western-blot assay was used to examine the expression of CTGF and HIF-1α. Results Hypoxia promoted the cell proliferation in all groups( P lt;0. 05) .Matrine inhibited the proliferation of WRC-5 cells in a concentration-dependent manner in hypoxia or normoxia conditions( P lt;0. 05) . The expression of CTGF andHIF-1αwas lower in normoxia and higher in hypoxia( P lt;0. 01) . Matrine inhibited the expression of CTGF and HIF-1αin a concentration-dependent manner in hypoxiaand normoxia( P lt;0. 05) . Conclusion Matrine can inhibit the cell proliferation and the expression of CTGF and HIF-1αof WRC-5 cells in normoxia and hypoxia in a concentration-dependent manner.
Objective To observe the effects of different doses of atorvastatin on bleomycin-induced pulmonary fibrosis in rats. Methods Seventy-five healthy female SD rats were randomly divided into five groups ( 15 rats in each group) , ie. a normal group , a model group, a 10 mg/ kg atorvastatin-treated group, a 20 mg/ kg atorvastatin-treated group, and a 40 mg/ kg atorvastatin-treated group. The rats in the model group and treatment groups were instilled with bleomycin in trachea( 5 mg/kg) , and the normal group were instilled with equal volume of normal saline. The treatment groups were gastric gavaged with different doses of atorvastatin each day from2 nd day on after instillation, and the normal group and model group were gavaged with normal saline. Blood samples were obtained from abdominal aorta in five rats in each group and blood gas analysis was performed on1st week, 2nd week and 4th week respectively after BLM instillation. Then the animals were killed and lung tissue samples were harvested for histopathology study. HE and Masson staining were used to determine the extent of alveolus inflammation and pulmonary fibrosis respectively.Histoimmunochemical stain were used to determine the protein levels of transforming growth factor-β1 ( TGF-β1 ) and connective tissue growth factor( CTGF) in pulmonary tissues. Results The arterial partial pressure of oxygenate ( PaO2 ) in the treatment groups were increased gradually with the increasing of therapeutic dose at each time point and decreased with prolongation of time in the same group. The protein levels of TGF-β1 and CTGF in pulmonary tissues were decreased gradually with prolongation of time. TGF-β1 and CTGF expressed obviously less in the treatment groups than those in the model group at each time point .The higher therapeutic doses were, the less the expressions of TGF-β1 and CTGF were. Conclusion Atorvastatin has remarkable inhibitory effects on BLM-induced pulmonary fibrosis of rats in a dose- and timedependentmanner.
Objective To explore the role of chronic ethanol ingestion in pulmonary fibrosis. Methods Twenty SD rats were randomly divided into a control group (n=10) and an ethanol group ( n=10) , and fed with quantitative non-ethanol and ethanol Lieber-DeCarli liquid diet every day respectively. All rats were sacrificed after 8 weeks. The morphological changes and collagen deposition of lung tissue were observed under light microscope by HE and Masson staining. Levels of glutathione (GSH) and hydroxyproline (HYP) in lung tissues were measured by colorimetric method. The content of connective tissue growth factor (CTGF) in lung tissue was detected by ELISA. Results Compared with the control group, varied degrees of alveolar and alveolar septal infiltration of inflammatory cells can be shown in the ethanol group, and also some alveolar wall damage or collapse.Masson staining showed that the ethanol group has more significant deposition of collagen fibers in alveolar interstitumthan the control group. The content of GSH in rat lung tissue reduced, but the contents of HYP and CTGF increased in the ethanol group compared with the control group [ GSH( mg/g) :0.08±0.04 vs. 0.22±0.14, HYP(mg/g) : 0.57±0.15 vs. 0.40 ± 0.09, CTGF(ng/mL) :306.57±46.86 vs. 134.02±79.82, Plt;0.05] . Conclusions Lieber-DeCarli ethanol liquid diet can establish a rat model of chronic ethanol ingestion. Lung injury and pulmonary fibrosis in rats can be induced by chronic ethanol ingestion. Ethanol may be one of the causes of the pulmonary fibrosis.
Objective To investigate the mechanismof lung injury caused by paraquat poisoning by observing the changes of fibrogenic cytokines in acute paraquat poisoned rats and the effects of pyrrolidine dithiocarbamate ( PDTC) . Methods Sprague-Dawley rats were randomly divided into three groups, ie. acontrol group ( n =6) , a PDTC group ( n =36) , a paraquat group ( n = 36) , and a paraquat + PDTC group( n =36) . The rats in the PDTC group, the paraquat group, and the paraquat + PDTC group were subdivided into 6 subgroups sacrificed respectively on 1st, 3rd,7th,14th, 28th and 56th day after the treatment. The levels of transforming growth factor-β1( TGF-β1 ) , platelet-derived growth factor ( PDGF) , insulin-like growthfactor-1 ( IGF-1) in serum were measured. Meanwhile the expression of connective tissue growth factor ( CTGF) and hydroxyproline in lung tissues were detected. The relationship of above cytokines with hydroxyproline was analyzed. Results The destructive phase in early ( 1 ～7 d) was characterized by hemorrhage, alveolar edema, and inflammatory cell infiltration. The proliferous phase in later stage ( 14 ～56 d) was characterized by diffused alveolar collapse with fibroblast proliferation and patchy distribution of collagen fibers. Compared with the control group, the level of TGF-β1 on all time points, the level of PDGF from7th to 56th day, the level of IGF-1 from3rd to 56th day in the paraquat group all significantly increased ( P lt;0. 01) . Immunohistochemistry results showed CTGF positive cells mainly located in aleolar epithelialcells, endothelial cells,macrophages in early stage, and fibroblasts were main positive cells on the 28th and the 56th day. The expression of CTGF in the paraquat group increased gradually compared with the control group on different time points ( P lt; 0. 05 or P lt; 0. 01) . Meanwhile, the levels of above cytokines were positively correlated with the level of hydroxyproline. Noteworthy, PDTC treatment led to significant decreases of above cytokines compared with the paraquat group in corresponding time points ( P lt;0. 05 or P lt;0. 01) .Conclusions Over expressions of IGF-1, TGF-β1 , PDGF, IGF-1 and CTGF may play important roles in lung fibrosis of paraquat poisoned rats. PDTC, as a b NF-κB inhibitor, may inhibits NF-κB activity and further significantly decreases expressions of cytokines, leading to significantly attenuated pulmonary inflammation and fibrosis. However, the mechanisms of PDTC intervention still remain to be explored.
Objective To investigate the effect of cryopreservation (CP) on the expression of connective tissue growth factor (CTGF) in the renal tubular epithel ial cells. Methods A total of 40 male Wistar rats (weighing 230-250 g) were used in this study. En bloc removal with in situ cooling both kidneys and hypertonic citrate adenine preservation solution were adopted. The rat kidney was be preserved 0, 12, 24, 36 and 48 hours at 0-4℃ (n=8), respectively. The expression of CTGF of renal tubularepithel ial cells was detected by using immunohistochemistry and in situ hybridization analysis. Results The expression of CTGF was less in CP 0 hour group and CP 12 hours group, the positive unit (PU) values of CTGF protein were 5.91 ± 2.30 and 5.57 ± 2.40 (P gt; 0.05), respectively, and the PU values of CTGF mRNA were 6.24 ± 2.79 and 6.51 ± 2.43 (P gt; 0.05), respectively. The PU values of CTGF protein increased at CP 24 hours group (10.25 ± 2.92), CP 36 hours group (14.31 ± 2.83) and CP 48 hours group (18.11 ± 3.94, P lt; 0.05), respectively, and the PU values of CTGF mRNA increased at CP 24 hours group (15.24 ± 3.95), CP 36 hours group (19.20 ± 4.73) and CP 48 hours group (23.09 ± 4.40, P lt; 0.05), respectively; showing significant differences when compared with CP 0 hour group and CP 12 hours group (P lt; 0.05). Conclusion CTGF expression may increase with severe cold ischemia injury, and might play an important role in regeneration and repair of renal tubular epithel ial cell injury.
Objective To investigate the delay of the denervated skeletal muscle atrophy with the method of restraining the increment of the connective tissues by tetrandrine and hormone. Methods The left hind limbs of 42 male adult SD rats were made into models of the denervated gastrocnemius, and then the rats were randomly divided into 3 groups, with 14 rats in each. In Group A, tetrandrine (8 mg/L）was injected into the denervated gastrocnemius; in Group B, triamcinolone acetonide（1.6 g/L） was injected; in Group C (the control group),normal saline was injected. Enough samples were obtained according to the different observation indexes at 30 days after operation. Electromyography, muscle wet weight measurement, light microscopy,electron microscopy,and microimage analysis were performed. ResultsThe fibrillation potential amplitude was 0.195 8±0.041 9 μV in Group A and 0.185 2±0.050 3 μV in Group B, and there was no significant difference betweenthe two groups (Pgt;0.05). However,in Group C the fibrillation potential amplitude was 0.137 7±0.058 9μV. The fibrillation potential amplitude was significantly greater in Group A than in Group C（Plt;0.05）. The muscle wet weight was 1.740 0±0.415 9 g in Group A and 1.940 1±0.389 4 gin Group B, and there was no significant difference between the two groups(Pgt;0.05).However, in Group C the muscle wet weight was 0.800 0±0.100 0 g. The muscle wet weight was significantly greater in Group A than in Group C（Plt;0.05）.The microscopy showed that more remarkable atrophy occurred in the control group. The muscle fibers were more complete, thicker and larger, with more nuclei and clearer cross-lines. More connective tissue and flat cells could be observed in Groups A and B. The myogenic protein amount was 440.124 2±46.135 6 in Group A and 476.211 4±41.668 8in Group B, and there was no significant difference between the two groups(Pgt;0.05).However, in Group C the amount was 380.040 0±86.315 9.The myogenic protein amount was significantly greater in Group A thanin Group C（Plt;0.05）. The muscle fiber number, diameter, cross section, and connective tissue increment were all significantly greater in Group A than in Group C（Plt;0.05）; however, there wasno significant difference between Groups A and B (Pgt;0.05). The electron microscopy showed that there were more degeneration changes, such as muscle silk disorder, chondriosome disappearance, and hepatin reduction, could be observed inGroup C than in Groups A and B. Conclusion Tetrandrine and hormone can delay the denervated skeletal muscle atrophy by restraining the increment of the connective tissues.
Objective To observe the influence of the transforming growth factor β1(TGF-β1) on the denervated mouse musclederived stem cells（MDSCs） producing the connective tissue growth factor（CTGF）at different time points in vitro. Methods MDSCs from the primarycultureof the denervated mouse skeletal muscle were isolated and purified by the preplate technique, and they were identified before the culture and after the culturein vitro with TGF-β1 (10 ng/ml) for 24 hours. Then, MDSCs were randomlydivided into 6 groups (Groups A, B, C, D, E and F) according to the different time points, and were cultured in vitro with TGF-β1 (10 ng/ml) for 0, 3, 6, 12, 24 and 48 hours, respectively. The levels of CTGF mRNA in MDSCs were measured by the real time RT-PCR and the expression of CTGF protein was detected by the CTGF Western blot. Results The immunohistochemistry revealed that before the adding of TGF-β1, MDSCs highly expressed Sca-1, with a positivityrate of 96%; however, after the adding of TGF-β1, the positive expression of Sca-1 decreased greatly, with a negativity rate gt;99%. The Western blot test showed that the ratios of CTGF to the average absorbance of βactin in Groups A-F were 0.788±0.123, 1.063±0.143, 2.154±0.153, 2.997±0.136, 3.796±0.153 and 3.802±0.175, respectively. In Groups AD，the absorbance increased gradually, with a significant difference between the abovementioned groups (Plt;0.05). However, in Groups D-F, there was no significant difference between the groups as the promotive tendency became less significant (P＞0.05). The RT-PCR test showed that the △Ct values in GroupsA-F were 1.659±0.215, 1.897±0.134, 2.188±0.259, 2.814±0.263,2.903±0.125 and 3.101±0.186, respectively. In Groups A-D, the increase in the △Ct value was gradual, but the differences were significant between the groups (Plt;0.05). But in Groups E and F, the promotive tendency became less significant（Pgt;0.05）. Conclusion TGF-β1 can promote the production of CTGF inthe mouse MDSCs cultured in vitro and the time-dependent relation exists for 3-12 hours.
Objective To explore the effect of connective tissue growth factor on the pathogenesis of hypertrophic scar and keloid tissue. Methods The content of hydroxyproline was determined and the expression of connective tissue growth factor gene was detected by the reverse transcription-polymerase chain reaction and image analysis technique in 5 normal skins, 15 hypertrophic scars and 7 keloid tissues. Results The contents of hydroxyproline in the hypertrophic scar(84.10±1.76) and keloid tissue (92.38±2.04) were significantly higher than that of normal skin tissue (26.52 ± 4.10) (P lt; 0.01). The index of connective tissue growth factor mRNA in the hypertrophic scar (0.78 ± 0.63) and keloid tissue (0.84 ± 0.04) were higher than that of normal skin tissue ( 0.09 ± 0.25) (P lt; 0.01). Conclusion Connective tissue growth factor may play an important role in promoting the fibrotic process of hypertrophic scar and keloid tissue.